Busway connector

ABSTRACT

Fish device for the electrical joining of conductors. The ends of the bars are pinched between contact plates simultaneously subjected to a well-distributed flexible compressive force developed along an axis on which they are stacked and limited in size by a sliding system. The device is applied to electric current-distributor cables containing bus-bars.

[ June 25, 1974 United States Patent [191 Joly 3,180,924 4/1965 174/88 3,733,575 5/1973 Gottschalk et 339/22 B e C n a H S, w n R0 on mm uh NH 0% CJ mm m wm MM W [73] Assignee: La Telemecanique Electrique, Primary Examiner-Bobby R. Gay

Monterre, France Assistant ExaminerRobert A. Hafer Feb. 9, 1973 App]. No.: 331,267

Attorney, Agent, or Firm-William Anthony Drucker [22] Filed:

[57] ABSTRACT Fish device for the electrical joining of conductors.

The ends of the bars are pinched between contact plates simultaneously subjected to a well-distributed flexible compressive force developed along an axis on which they are stacked and limited in size by a sliding system.

The device is applied to electric current-distributor cables containing bus-bars.

[56] References Cited UNITED STATES PATENTS 4 Claims, 6 Drawing Figures 2,932,686 4/l960 Herrmann..........,.................. 174/88 3,031,521 4/1962 KrauSS et 174/88 B SHEET 1 OF 3 PATENTEDJUH 25 I974 FIG.1

mimzmunzs m SHEET 2 OF 3 Fl G. 2

PATENTEI] JUN 2 5 I974 FIG. 5-

BUSWAY CONNECTOR The invention relates to a fish device for electrically connecting sets of current-distributor bus-bars placed end to end, including a common clamping component consisting of a cylindrical pull-rod fitted with mobile ramps cooperating by rotation with fixed ramps and a plurality of contact plates each associated with an insulating cheek and threaded on the pull-rod so that the relative movement of the ramps is translated by a simultaneous axial flexible compression of the contact plates on the bars.

Such a device is particularly applicable to current transport systems usingbus-bars protected by a metal sheath.

Fish devices of the type described above are already known, notably in US. Pat. No. 3,384,855. In these known devices, the pressure provided by the flexible means is not distributed over a large surface, which causes the insulators to creep under the effect of a high unit pressure and a mechanical deterioration of the latter arising from the considerable mechanical stresses to which the conductors are subjected in case of a shortcircuit on the line.

Moreover, the device providing the flexibility can be subjected to a high strain which will be translated by a locking of the ends of the bus-bars which is detrimental to the extent to which it destroys the freedom of movement of these ends under the effect of thermal dilatations. Finally, the units used to produce this flexible effect are only flexible when they are assembled in a specific way, which gives rise to the possibility of malfunction due to assembly errors.

The invention thus proposes to provide a .fish system in which steps will be taken to ensure that the unit pressures exerted on the insulators are low and independent of the movement which may be imparted to the compression device.

At the same time, it aims at providing a device in which inversion of the position of certain parts during assembly is not translated by any disturbance of the properties obtained by means of the above-mentioned arrangements.

In accordance with the invention, this result is achieved by means of the fact that the axial compression movement of the flexible components, which are distributed between the facing insulating cheeks of two neighbouring bars, is interrupted when a friction couple exceeding a specific value is developed between the ramps.

In accordance with a complementary characteristic of the invention, each of the flexible components consists of two symmetrical, flat units having a bearing surface similar to that of the contact plates, between which is arranged a plurality of springs distributed substantially symmetrically in relation to the axis of the pull-rod on which each component is threaded.

In a particularly advantageous embodiment of the invention, the fixed ramps consist of four portions with helical surfaces arranged at an angle of 90 to one another and each having in the vicinity of its highest area a hollow into which ratches a projection representing one of four mobile ramps carried by one same disc, rotatingly mobile and fitted with a control lever.

Other useful peculiarities of the invention will be brought out by the'description below and by the following figures, where:

FIG. 1 shows an elevation view of the fish with a partial section along the axis of the protective sheath.

FIG. 2 shows a split section view of the fish along the line AA.

FIG. 3 shows an elevation view of the fish when the locking device is loosened.

FIG. .4 shows a sectional view of a variant.

FIG. 5 shows a left-hand view of FIG. 4.

FIG. 6 illustrates an embodimental detail of the fixed and mobile ramps.

FIG. 1, which illustrates a general view of the apparatus 1, shows a length of metal sheath, rectangular in section, which is designed to provide electrical and mechanicalprotection for bus-bars transporting industrial current. The fish device represented by the general reference 5 serves to provide the electrical and mechanical connection between the ends of two sets of bars 7 and 8.

At the top of the sheath is a rectangular opening 4 through which the fish device will be inserted vertically from top to bottom. This latter is held laterally by the edges of the opening 4 and vertically by protuberances 6 placed on the top of it. The compressing device which bears the general 9 is in particular equipped with an operating lever 10 the end of which comes to a position in the vicinity of a cover 2 pivoted at 3 on the sheath 1. In FIG. 1, the levers position corresponds to the compressed position of the fish device.

The sectional view illustrated in FIG. 2 shows that the system as a whole is arranged inside the piping and that consequently the compressing device can only be operated with the cover open. In the same figure, 7, 7', 7", 7" denote the ends of a set of bus-bars; each of these ends comes to aposition between two contact plates of identical shape '11, 12 with, in the middle part thereof, protuberances 13 and 14 also visible in dotted lines in FIG. 1. These protuberances belonging to plates 12 and 11 can come incontact when the ends of the bars 7 are not engaged between the contact plates but do not touch in the opposite case.

They are designed to provide suitable spacing when the device is put in position and also encure that it is positioned substantially symmetrically in relation to the ends of the sets of bars 7 and 8.

With each of the contact plates 12 and l 1 there is associated an insulating cheek 16 and 17 respectively, designed on the one hand to keep the plates in position by means of a special hollow, and on the other hand to transmit and/or receive a lateral thrust to/from the corresponding components associated with the bars 7 7", 7". Each of these insulating checks, which are made of a suitable plastic material so that they do not creep under a clearly specified load, has a centring barrel 18 and 19 respectively which encase with one another, the barrel l9 moreover serving to preserve an adequate escape line with a metal compression rod 20 on which it is mounted. It is clear that the contact plates 11 and 12 will also be provided with openings sufficient to enable them to be mounted around the barrel 18. The end of the neighbouring bar 7 which is similarly equipped with cheeks 16', 17' is associated with the neighbouring cheeks by guide components and flexible units. To ensure an identical angular positon around the compression rod 20, the check 16' opposite the check 17 of the neighbouring bar is fitted with a nipple 24 which penetrates into a housing 25 in the latter. Similar measures are moreover taken on all the cheeks to ensure proper alignement. The guiding device which has just been described moreover makes it possible to ensure the proper working of a generally flat-shaped flexible unit which is positioned and held between two opposite cheeks such as 16' and 17 and which is made up of two shoes 22 and 23 of the same shape which can encase with each other, with play, by turning.

Springs such as 21, 21 are arranged between the two shoes and stretch to separate these.

Their number and their rigidity depends on the compressive force required on the contact bars, and this is itself a function of the contact pressure necessary simultaneously to ensure low contact resistance and friction which does not oppose the bars dilatation movements. Conductive grease can be applied to the surfaces to facilitate their movement. The surface of the shoes is substantially equal to that of the contact plates to which they must communicate a certain amount of pressure. The positioning of the springs is governed by the need to distribute the pressure uniformly; they will in general be distributed symmetrically in relation to the axis of the rod 20. The embodiment selected for the flexible components means that an extremely flat component is available whose rigidity may be selected as a function of requirements; moreover, the symmetrical layout provides absolute safety on assembly; finally, the whole unit does not need to be prepared when assembly is done and can be stored or even coupled to meet load balancing requirements.

The stacking of the contact plates, insulating cheeks and flexible components on the compression rod 20 is maintained by means of two stop plates 26 and 27 which are kept in contact with the rod 20, the first by permanent riveting, the second via a compression device 9 which will be described below. When said compression device is not clamped, there is axial play along the compression rod between all the components which it passes through. This play makes it possible easily to put the fish device in position irrespective of any defects in alignment between the ends of the sets of busbars.

In the position where the compression device is not clamped, the two shoes are applied one against the other by the springs, which are subjected to prior straining.

The compression device 9 consists in particular of a bearing plate 28 which is housed in an external hollow of the cheek l6 and threaded on the compression rod.

This bearing plate carries on its outside surface four projections obtained by stamping and forming four helical ramp portions 29, 29', 29", 29", see FIG. 3 in particular. Each of these ramps, arranged at an angle of 90, comprises in the area close to the summit a hollow 30 which precedes by a short distance the side edge 33 where the ramp comes to an end.

The stop plate 27 consists of a disc fitted with three arms 31 and a control lever positioned at, an angle of 90 to one another. All the arms and the lever are ribbed so as to mark out ramp portions 32 (see also FIG. 6) designed to cooperate with the ramps 29. When a relative movement is established between the latter, an axial movement occurs producing the compressing action required until such time as the ramp 32 racks into the hollow 30. This position, which is the working position, corresponds to the judicious compression of the bars between the contact plates and must not be exceeded. If any attempt were made to increase the compressive force, the ramp 32 would come out of the hollow and break the mechanical contact, so

that any prohibitive compression would be prevented. 5 It will be appreciated that when the compression device is not clamped, the control lever prevents the closing of the cover.

An embodiment variant illustrated in FIGS. 4 and 5 makes use of a compression rod 40 comprising at one end an operating head 41 suitable to take a key and at the other end a threaded portion 42 the thread of which represents the mobile ramp. The fixed ramp cooperating with the latter consists of the inside thread of a solid body 43 generally revolving in shape comprising flat surfaces 47 and peaks 48. Two pring blades 46, 46 held in grooves 49 in a bearing plate 44 are applied against the flat surfaces to stop the rotation of the solid body 43.

The unit operates like a bolt in a nut until such time as the axial compressive force causes 43 to be driven by 42 counter to the flexible force of the spring blades.

A force exceeding that producing the sliding movement cannot consequently be produced, which is in fact the result sought.

For the device to work reliably, it may be necessary to position between the part 43 and the bearing plate 44 a component 45 with very good slip characteristics. For example, the choice will fall on materials possessing very good antifriction properties, perhaps even radial needle bearings.

It is clear that this latter arrangement may lend itself to variants, without thereby departing from the framework of the invention in accordance with which the relative movement between ramps is interrupted when the compressive force exceeds a certain value.

As regards the first embodiment illustrated in FIGS. 1 to 3, modifications could also be made to the compressing and flexible devices. For example, springs in the form of strips or corrugated rods could be used, or even wire cloth plates, without departing from the framework of the invention.

With the ramps, rollers, with a view to facilitating.

movement, couldbe used, while spacing systems providing a considerable force with a relatively small compression travel, such as knukle joints, could perform the function of the above-mentioned ramps.

What is claimed is:

1. A connector for an electric line fitted with bars comprising:

a. a large number of pairs of insulating plates (16, 17 parallel to one another, equal to the number of bus bars (7) to be connected, and arranged side by side;

b. for each pair of plates, a pair of contact elements (11, 12), each arranged against the side of each insulating plate directed towards the other plate of said pair of plates, said contact elements (l1, 12) being separated by an interval of approximately the thickness of the bus bars and being of a length such that they rest on the portions of bus bars inserted between the insulating plates of said pair;

c. a pair of meta] supporting parts (22, 23) arranged between two insulating plates opposite one another, and belonging respectively to two pairs of adjacent insulating plates; a large number of elastic components (21) separating the said supporting parts;

d. a first and a second clamping plate (26, 28) arranged respectively against the sides of the most distant insulating plates belonging to the first and last plate of said large number of pairs of plates;

e. an insulated rod(20) passing freely through the insulating plates, the contact elements, the supporting parts, the second clamping plate (28) and connected axially to the first clamping plate (26);

f. at least one inclined ramp (29) carried by the second clamping plate concentrically with said rod, and clamping means (27) forming axially one part with the rod (20) and bearing on the ramp to compress the elastic elements by relative rotation of the ramp and the clamping means; and

g. limiting means to interrupt relative axial movement between the ramp and the clamping means when a predetermined compression of the elastic components has been reached.

2. A connector according to claim 1, in which means (24, 25) are provided to prevent the relative rotation of two adjoining insulating plates, said limiting means comprising a lever (10) pivoted on the rod (20), and secured axially by a wide part (15) of said rod, and supporting at least one arm (31) bearing on at least one inclined ramp which has a non-inclined region (32) where the movement of the arm does not cause a relative axial shift between said arm and the ramp.

3. A connector according to claim 1, in which said supporting devices bear on said insulating plates on a surface close to the surface of application of said contact elements on said insulating plates.

4. A connector according to claim 1, in which said supporting parts are applied to said insulating plates on a surface close to the surface of application of the said contact elements on said insulating plates, and said limiting means comprise a spiral ramp carried by a solid member (43) of regular polygonal shape whose sides (47) are kept stationary by the pressure of at least one elastic part (46) which bends on passing one of the peaks (48) of solid polygon when the frictional couple transferred by another spiral ramp (42), part of the rod (40), exceeds a predetermined value. 

1. A connector for an electric line fitted with bars comprising: a. a large number of pairs of insulating plates (16, 17) parallel to one another, equal to the number of bus bars (7) to be connected, and arranged side by side; b. for each pair of plates, a pair of contact elements (11, 12), each arranged against the side of each insulating plate directed towards the other plate of said pair of plates, said contact elements (11, 12) being separated by an interval of approximately the thickness of the bus bars and being of a length such that they rest on the portions of bus bars inserted between the insulating plates of said pair; c. a pair of metal supporting parts (22, 23) arranged between two insulating plates opposite one another, and belonging respectively to two pairs of adjacent insulating plates; a large number of elastic components (21) separating the said supporting parts; d. a first and a second clamping plate (26, 28) arranged respectively against the sides of the most distant insulating plates belonging to the first and last plate of said large number of pairs of plates; e. an insulated rod (20) passing freely through the insulating plates, the contact elements, the supporting parts, the second clamping plate (28) and connected axially to the first clamping plate (26); f. at least one inclined ramp (29) carried by the second clamping plate concentrically with said rod, and clamping means (27) forming axially one part with the rod (20) and bearing on the ramp to compress the elastic elements by relative rotation of the ramp and the clamping means; and g. limiting means to interrupt relative axial movement between the ramp and the clamping means when a predetermined compression of the elastic components has been reached.
 2. A connector according to claim 1, in which means (24, 25) are provided to prevent the relative rotation of two adjoining insulating plates, said limiting means comprising a lever (10) pivoted on the rod (20), and secured axially by a wide part (15) of said rod, and supporting at least one arm (31) bearing on at least one inclined ramp which has a non-inclined region (32) where the movement of the arm does not cause a relative axial shift between said arm and the ramp.
 3. A connector according to claim 1, in which said supporting devices bear on said insulating plates on a surface close to the surface of application of said contact elements on said insulating plates.
 4. A connector according to claim 1, in which said supporting parts are applied to said insulating Plates on a surface close to the surface of application of the said contact elements on said insulating plates, and said limiting means comprise a spiral ramp carried by a solid member (43) of regular polygonal shape whose sides (47) are kept stationary by the pressure of at least one elastic part (46) which bends on passing one of the peaks (48) of solid polygon when the frictional couple transferred by another spiral ramp (42), part of the rod (40), exceeds a predetermined value. 